Question

A ray of light is incident on a rectangular block of glass of index of refraction 1.450cm at an angle of 40 degree as shown in the figure. if the thickness of the block is 4.00 cm. find the amount d by which the ray is deviated.

Answer 1

Answer:

There could be error as i used small angle approximation... But the method is given

Answer = 4 sin40

Explanation:

If u know value of sin40 then find x amd procced accordingly

Answer 2

Hey Dear,

◆ Answer -

Deviation = 1.289 cm

● Explanation -

# Given -

i = 40 °

n = 1.45

t = 4 cm

# Solution -

According to Snells law -

n = sini / sinr

sinr = sini / n

sinr = sin40° / 1.4

sinr = 0.6428 / 1.4

sinr = 0.459

r = 27.33°

Ray of light is expected to fall at -

d = t.tani

d = 4 × tan40°

d = 3.356 cm

Ray of light actually falls at -

d' = t.tanr

d' = 4 × tan27.33°

d' = 2.067 cm

Amount by which ray of light is deviated is -

∆d = d - d'

∆d = 3.356 - 2.067

∆d = 1.289 cm

Therefore, ray of light deviates by 1.289 cm.

Hope this helped you.